Published on August 31st, 2013 | by James Ayre3
Drinking Water From Fracking Waste? Researchers Propose Using Gas Hydrates Produced By Fracking To Desalinate Wastewater Produced By Fracking
August 31st, 2013 by James Ayre
Drinking water from fracking waste? Almost sounds too good to be true, right? Or perhaps more like a headline from The Onion? Researchers are now proposing a very questionable solution to freshwater scarcity in the water-poor regions of the world — simply take the extremely toxic wastewater produced by hydraulic fracturing and put it through an imperfect purification/desalination process. Mmmm. Sounds good, doesn’t it?
Sort of makes you wonder where the funding is coming from.
The proposed method — known as gas hydrate desalination — works by producing gas hydrates from the wastewater and then allowing the hydrates to separate. It isn’t a new technique, but the researchers have apparently made some improvements to earlier methods.
The press release explains the technique:
A gas hydrate consists of only water and a gas such as methane, the stuff of natural gas. Thus, when hydrates form, salts and other impurities are left behind. When the hydrate breaks down, the gas and pure water are released. However, forming the gas hydrate used in desalination required costly chilling of the water to 28 degrees Fahrenheit. Researchers Yongkoo Seol and Jong-Ho Cha sought to develop a less costly version of the method, which involves a variation on methane hydrates, chunks of ice retrieved from deep below the sea that burst into flame when brought to the surface.
They describe development and laboratory testing of a new type of gas hydrate desalination technique. They formed the hydrates from water and carbon dioxide with the gases cyclopentane and cyclohexane, which made the method work more efficiently. It removed more than 90% of the salt compared to 70% with the previous gas hydrate technique. And the process works at near-room temperature, reducing the need for chilling.
With a water source as toxic as fracking wastewater, though, you would think that the researchers would note that a 90% removal rate of salt and other ‘impurities’ likely isn’t going to cut it. And beyond any of that, it’s just hard to imagine such a method being economical on a large scale. But when you look at regions like south Texas, that are in states of extreme drought but still seeing as much as 25% of their very limited water supplies go towards fracking, even while agriculture and cattle ranching in the region is drying up, the approach makes a bit more sense. Or I should say that the desperation for some good PR makes a bit more sense….
Something else to note, though — the quantity of wastewater that can be recovered from fracking is actually rather limited anyways, only 20-25% on average, so even with an effective economical means of treating the water, fracking is bad news for water-scarce regions.
The new research was just published in the journal ACS Sustainable Chemistry & Engineering.
For more information on fracking see:
- 30 Texas Towns Will Be Out of Water, Because: Fracking
- The Fracking Chickens Are Coming Home To Roost
- Fracking Waste: Too Toxic, Even For A Hazardous Waste Site
- Obama’s Fracking Frenzy: Caving In To Industry, “Giving Polluters A Free Ride”